I don't have any experience with the pens but have used a Spotone process for... well, forever. I use a favorite 15/0 brush (15 0's rather than a 000 or 0 or whatever). I've had this particular brush almost from the beginning of my spotting life, yet to find another 15/0, 000, 00, 0 or whatever quite as good. Anyway, the Spotone is mixed on a small tile as per the paper type it is to match and let dry (for a paper new to ones usage it may take several attempts at different mixes to get an acceptable match, but the documentation that comes with the Spotone is a good starting point). One mix will last me months. When spotting, I just add enough moisture to the brush in order make the dried Spotone mix liquid again and then only enough Spotone to make the right density for the area to be spotted. I put the brush in my mouth for just a very little bit of moisture as dipping it in a water source tends to be too much liquid for my technique [and please don't tell me what this will or has done to me, I’m not sure I want to know])... Keeping scraps of fully processed paper of the type to be spotted (processed in the same chemicals and toned the same way). these are used when spotting to insure the correct density mix for the print (placing the scrap next to the area to be spotted). I dab the Spotone on rather than using brush like strokes, like trying to make tiny dots until the area is ‘spotted’.